Motor-drive



J i. WOOD.

MOTOR DRiVE.

APPLICATION FILED 130.17} 1914. RENEWED v1M4. 12, [916.

1 1 93, 1 05 Familial Azig. l'fibk 2 SHEETSSHEET E Witnesses: gnv-entms w xfiwm, m w W b5 Q J. J. WOOD.

MOTOR DRIVE.

APPLICATION FILED 0c.17,1914. RENEWED JAN 12,1916.

1,1 93,105, Patented Aug. 1, 1916.

2 SHEETSSHEET Z F12. Z.

lllllllllllllftl ffiwm Witmassss: lnVentor:

'ZZW M James J.Wood,

H is Attorneg.

UNITED STATES PATENT OFFICE,

JAMES J. WOOD,

0F FORT WAYNE, INDIANA, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MOTOR-DRIVE.

Specification of Letters Patent.

Patented Aug. 1, 12916,

Application filed December 17, 1914, Serial No. 877,689. Renewed January 12, 1916. Serial No. 71,804.

To all whom it concern Be it known. that I, JAMES J. VVoon, a citizen of the United States, residingat Fort \Vayne, in the county of Allen, State of Indiana, have invented certain new and useful In'iprovements. in MotorJDrives, of which the following is a specification.

' My invention relates to motor drives, and is particularly applicable to such drives for sewing machines. It has heretofore been proposed to control such a motor drive by means of a system of springs and levers, a circuit closer and a brake, both the circuit closer and brake being controlled by presof my invenolioiving descriptiontaken in c n M. ac- Cpmpanynig drawings, 1 \Vhicli- Figure l is a transverse vertical sectionof a sewing machine embodying my invention with the portions outside the plane of section indicated in dotted lines; Fig. 2 is araginentary detail view showing the motor with its controlling devices in normal position; and Fig. 3 is a view similar to Fig. 2, but with the controlling devices in extreme actuated position.

Referring to the drawings in detail, and especially to Fig. l, l is the supporting stand upon the top of which is mounted the usual table 2 and the machine platform 3 in which is countersunk the supporting base 4 having secured thereto the bed plate 5 of the sewing machine. The sllp 'iorting base 4i is sup ported Within the platform at the rear by means of the socket hinge (3, and at the front by the ledge or shoulder 7, which engages a complementary ledge 8 on the front portion 3 of the platform 3. This front portion 3 is connected with the table 2 by means of the socket hinge 9 so that it may be lifted out of the path of the machine when the ma chine and its supporting base 4 are lowered into the storage chamber 10, the base 4 being supported in its lowered position by the stop 10'. The sewing machine proper consists of the usual pillar ll and horizontal arm (not shown) Which supports the drive Wheel 13 and contains the usual mechanism for transmitting motion from the drive Wheel to the needle liar, and the hollow bed plate 5 containing: the usual shuttle and feed mechanism, and means for transn'iitting, motion thereto through the pillar from the drive Wheel. A foot power mechanism is mounted in the stand l, consisting of the treadle 16 pivoted to the stand at 1,7 and adapted to transmit its n'iotion through a connecting rod 18 to the crank ll) of a main drive Wheel 20, IXHHS! lacing transmitted from said main drive wheel to the drive Wheel 35 of the machine by the driving belt 21. These parts may he of any "Well known or usual construction.

The motor drive for the in plate 5 in any suitable of lugs or brackets and boll pass through hollow spat-in no; motoriZQ is provided wii'l l ing a brake drain niounte or shaft of the motor and a A switch 65 is nioruiteal on brake and switch are operated by e hralce lever 20 and the floating; switch love" 27,.

respectivelyv The floatingswitch lever connected at one end to the switch (35 an? at the other end to the brake lever L li throu a retractile sprin A rctractilc spring: 29 isalso connected to the lever 2'? oppose the tension of spring 28. An. operat mg or pull device connected to the switch lever 27, consisting of an elm-fated link 30,, extending downwardly fli'flllllil and below the brake lever .26, and a chain 31. This pull device is adapted to be connected with the far end of the treadle by means of the hook provided for the purpose. This connection, of course, made only when the motor drive is to he used. Power is lll"ziil5- niitted from the driving pulley 33 of the motor to the pulley '13 of the machine by means of a drive belt 34, the drivihghelt 21 being loosened or disabled henever the motor drive is used r 1 Lil? Referring to the controlling mechanism 1 in detail, attention is called to Figs. and 4 3, in which the motor and controlling meclr anism are shown. The motor switch con-- sists of the contact members 36, 3'? arranged in if-formation and adapted to be bridged by the conducting roller The roller 38 is carried on the end of a switch arm 39 pivoted at l0 to the casing of the motor. The right hand end or" the floating switch lever 27 is provided withan elongated eye or slot ll which fits over the pivot l0 and slides vertically thereon. A tension spring 42 connects at one end to a pin 43 attached to the free end of the switch arm 39 andat the other end to the switch lever 27 .at a point is above the line connecting the pin 43 and pivot 40, when the parts are in the normal position shown in Fig. 2. The switch lever 27 is. held up in the position shown in Fig. 2 by the relatively strong retractile spring 29, which is connected at one end to the lever at the point 25, and is sup ported at the other end by a pin 46 fixed in relation to the machine. The pin 46 is carried on the yoke 47, which also carries at v its lower end a stop pin 48 for limiting the downward movement of the switch lever 27. The brake lever 26 is pivoted to the motor casing at so, and carries near its pivoted end a brake shoe 6-; pivoted to the lever at 50. This brake shoe is hung oil center, as clearly seen fr the drawings, which prevents the same from chattering. It is normally held tightly against the brake wheel 51 under tension of the relatively weak spring 28, which connects the free end of .the brake lever to the free end of the switch lever 27 at points 52 and 53, respectively. A conducting cord 60 is provided for the purpose of effecting connection of the motor with an electrical supply circuit,

which may be either direct "or alternating current. The switch lever 27 is operated through the link which is connected thereto at the point 54 and passes downwardly free or the brake lever and on each side thereof, connecting ,below the brake lever with the chain 31. Suitable stop pins 55 and are carried at the right hand end of the switch lever for bringing the switch lever into positive connect-ion with the switch arm 39 when in either of its extreme positions, so that in case the spring 42 breaks, the switch arm 39 will nevertheless be positively operated by these pins.

The operation of the r achine is as follows: Assuming that the motor driving belt 34, the chain 31 and treadle 16 are connected. up as shown in Fig. l, and that the windings of the motor are connected to a suitable source of current in circuit with the switching means, the operator rocks the treadle so as to gradually pull down on the chain 31. As the chain and its link connection 30 move downward, the switch lever 27 first swings around a point to the left of point 45, the right hand end moving down, guided by the slot 4:1 and pivot 40, until the uppermost end of the slot engages the pivot. is the right hand end of the switch lever 27 moves downward, it carries the point lei below the line passing through the pin 43 and pivot 40, so that. just before the upper end of the slot 41 strikes the pivot 40, the direction of pull of the spring 39 is shifted to a point below the center of the pivot 40, which causes the switch arm 39 to snap down into the position shown in Fig. 3, bringing the bridging member 38 into engagement with the contacts 37, 36. I

When the switch is actuated to closed position, as above described, the circuit of the motor is completed and the motor armature and field winding are connected in series directly across the supply circuit with-f out the interposition of any resistance, and it therefore immediately exerts its maximum torque. The tension of spring 28 has not however, been appreciably relieved, and consequently the brake '64 is still applied to the motor armature and prevents it from rotating. Further motion of the treadle to pull down on the chain 31 now swings the leverv 27 about the pivot 40 and relieves the tension of the spring 28, which relieves the tension on the brake lever 26 and consequently the pressure of the brake 64. The motor armature now begins to rotate, rotating the brake wheel 51 and pulley 33, all of which are connected to rotate together. This motion of the pulley is transmitted to the machine by the drive belt 34 which starts the machine to working. If the tension of spring 28 has been only partially relieved, the pressure of the brake shoe 6%- against thebrake wheel 51 is only partially reduced, so that the motor and machine run at minimum speed. If the chain 31 is moved downward to its lowest limit, the lever 27 swings aboutthe pivot 40.

against the tension of the relatively strong,

spring 29 until it finally strikes the stop pin 48, the downward movement of the free end of the lever 27 reducing the tension of the spring 28 to a minimum, which in turn re-- duces the pressure of the brake shoe 64 on i the brake wheel 51 to a minimum. The gradual reduction of the tension of the spring 28 to a minimum proportionally reduces the pressure of the brake shoe on the brake wheel, thereby gradually reducing the braking effect on the armature of the motor and permitting a gradual increase of speed until the limit is reached. When the treadle 16 is gradually rocked back so as to permit the switch lever 27 to move back into the normal position indicated in Fig. 2, under tension of the relatively strong retractile spring the switch lever first swingsup- 'ward around the piyot 40, gradually increasing the tension on spring 28, which in turn gradually increases the pressure of the brake shoe on thebralte wheel of the motor, thereby causing a gradual reduction in the speed of the motor until the motor is finally brought to standstill, then the spring 29 causes the right hand end of the lever 27 to move upward on the pivot until the lower end of the slot il strikes said pivot, which upward movement of the lever again carri the point it to normal position above the dead. center line as indicated in Fig. 2. As soon. as the point it reaches its normal position, the direction of pull of the spring 42 is moved above the center of the pivot 40, which causes the switch arm 39 to snap up into the normal disconnected position, as indicated in Fig 2, whereby the circuit ofthe motor is opened. It wiil thus be seen that by method of control, the use of complicated flexible transmission is done away with, and. that the power output of the n'iotor is regulated directly by the pressure of the foot on the trcadle, which method of regulation comes most natural to the oper ator, and rend the device easy of operation without specialinstruction in its use.

It i

obvious fr'inr the drawings that the 4 may be 'iedally operated by disenj ng the belt 34 from the drive wheel 13 and throwing the belt 21 into engagement with the drive wheel 35.

It will be obvious to those skilled in the artthat various modifications may be made without. dept rting from the spirit oi the in ven 'iicn, and l wish it fully understood that mo ications are contemplated by a fall within the scope of the appended 'n as new, and desire to secure oi the United States is ration, a machine having-acan electric motor adapted to means, and means'iior tor comprising brake oi'or spindle, a brake lever, r'itor supply circuit, a floatld at one end to said switch Ll and through tension means a lever, intermediate tension rd in said lever so as to opi, lever tension means, and an "on for the switch lever oppose theiast mentioned tension that when pressure is exerted upon eh will first close and thereafter on the tension device of the brake be progressively decreased.

ination, a machine having acelectric-motor adapted firing means, and means f said motor comprising a the motor spindle, a brake v. one si: thereof, a switch tor supply circuit, a floating lever at one end to said switch and at end through tension means with the brake lever, intermediate tension' 'means connected to said lever so as to opl ose the brake lever tension means, and an a mating connection for the switch lever adapted to oppose the last mentioned tension means so that when pressure is exerted upon it-the switch will first close and thereafter the strain. onthe tension device of tli'esbrake lever will be progressively decreasedr 3. In combination, a machine having actuating means, an electric motor adapted to drive said actuating means, and means for controlling said motor comprising a brake drum on the motor spindle, a brake lever pivoted at one side thereof extending across to the other side and carrying a brake shoe bearing on the drum, a switch for the motor supply circuit, a lever connected at one end to said switch and at the other end through tension means with the brake lower, intermediate tension means connected to said lever so as to oppose the brake lever tension means, and an actuating connection for the switch lever adapted to oppose the last men-- tioned tension means, so that when pressure is exerted upon it the switch will first close and thereafter the strain on the tension device of the brake lever will be pr0gressivcly decreased.

4. In combination, a machine having actuating means, an electric motor adapted to drive said actuating means, and means for controlling said motor comprising a drum on the motor spindle, a brake shoe bearing thereon, a transverse lever pivoted at one end and carrying said shoe intermediate of its ends, a switch for the motor circult, an actuating lever for said switch, a relatively strong tension member extending from said lever to a fixed anchorage, and normally exerting strong tension on the lever to keep the switch open, a relatively weaker tension member connected between the ends of the'switch lever and the brake lever and hori'nally maintaining the brake shoe in en.- gagement with the drum under b 'aking pressure, and a pull device connected to the switch lever between the tension devices and the switch, the parts being so arranged and connected that a direct pull upon said pull device will first act against the relatively strong spring to move the switch lever and thereby throw over the switch into closed position, and a continuation of said pull will then move the switch lever upon the switch as a pivot against the tension of the relatively strong spring member, to relax the tension of the relatively weaker tension member and thereby decrease ,the pressure of the brake shoe upon the braking drum.

5. In combination, a machine having actuating means, an electric motor adapted to drive said actuating means, and means for controlling said motor comprising a brake drum on the motor spindle, a brake shoe bearing thereon, a lever pivoted at one end' to the motor structure and carrying said brake shoe, a make and break switch mounted on the motor field structure opposite the brake mounting, a lever having a slotted connection with said switch so as to allow lost motion, and pair o t tension springs of unequal strength, the weaker spring connecting the outer or free ends of the said levers, and the stronger spring connecting a point near the outer end of the switch lever to a fixed abutment, and a pull device connected to the switch lever at a point between said stronger spring and the switch, whereby a normal distribution of forces will maintain the switch lever in totally retarded position with its slotted end holding the switch open, and its other end maintaining iaximum tension on the brake lever spring, but pressure exerted on the pull device will first move the slotted end of: the switch lever to close the switch and then will turn said lever upon the switch pivot against the tension of the stronger spring to relax the tension on the brake lever spring.

6. in combination, a machine having actuating means, an electric motor adapted to drive said actuating means, and means for controlling said motor comprising a drum on the motor spindle, a brake shoe hearing on the drum, a pivoted brake lever carrying said shoe, a. pivoted make and break switch for the motor circuit, switch lever having a slot traveling on the same A pivot as the switch and having a snap spring connection with the switch arm adapted to be moved past center in one direction or the other as the lever moves from side to .side to the limits of its slot, a tension spring connecting the free ends of the brake lever and the switch lever, and a stronger tension sprin opposing the first mentioned spring and connecting an intermediate point on the switch lever to a fixed anchorage, tension on said stronger spring normally maintaining the switch lever at its pivot end retracted to the limit of its slot and the switch open, and at the other end retracted against the weaker tension spring to place the strain upon the brake lever, and a pull device secured to the switch lever at a point between the connection of the stronger spring and the pivot slot, the pull device when operated acting against the stronger spring to first pull over the switch end of the lever to the limit permitte'd by its slot and thereby close the switch, and" thereafter to overcome the tension of the stronger spring and move the free end of the switch lever around the switch pivot so as to relax the tension on the brake spring and thereby the pressure exerted by the brake on the drum.

7 In combination, a machine having actuating means, an electric motor adapted to drive said actuating means, and means for controlling said motor comprising a drum Onthe motor spindle, a brake shoe bearing on the drum, a pivoted brake lever carry ing said shoe, a pivoted make and break switch for the motor circuit, a switch lever having a slot receiving and traveling on the pivot of the switch and having a snap connection with the switch arm and a pair of opposite stop pins for holding the switch open or closed, according to the position of the lever, said snap spring adapted to be moved past center in one direction or the other'as the lever moves from side to side to the limits of its slot, a tension spring connecting the free ends of the brake lever and the switch lever, and a stronger tension spring opposing the first mentioned spring and connecting an intermediate point on the switch lever to a fixed anchorage, tension on the said stronger spring normally maintaining the switch lever at its pivot end retra cted to the limit of its slot and the switch open, and at its other end retracted to pull on the weaker tension spring and thereby place a strain upon the brake lever, and a pull device secured to the switch lever at a point between the connection of the stronger spring and the pivot slot, the pull device when operated actin against the stronger spring to first pull over the switch end of the lever to the limit permitted by its slot and thereby close the switch, and thereafter acting against said pivot as a fulcrum to overcome the tension of the stronger spring and move the free end of the switch lever around the switch pivot so as to relax tension on the brake sprin and thereby the pressure exerted by the brake on the drum. I

In witness whereof, I have hereunto set my hand this 9th day of December, 1914.

JAMES J. WOOD. Witnesses A. L. HADLEY, G. A. BORGHERT.

It, is hereby certified that in Letters Patem Na 1, 32 23 165, granted. August 1, 1916,

upon the application sf James J. W00 i, 9f Fm f ment in fMotor-Drives, an error appgairs in theprinwd Bpacification requiring correctionas follows: Page 4, line 74, clgxim 7, after the word snap inseam the word spring; and that the said Letters Patent should be read with ibis aarreatiun thergip that the SM-IIG may conform to the record of the case in t-helmteni; Office.

Signed and sealed this 5th day of September A 79., 1916 [emu] F, CLAY,

Aeting Comnizsiamr 3f Patents.

Wayne, Elczuiiwa, for an improve- Ht, is hereby certifitd that in Lattats Patent N5. 11, 15193 105, granted August 1, 1916,

upon the application of James J. Wood, f Fen-t Wayna, hdia-na, for am improvement in Motor-Drives, am error appears in theprinted tspecification requiring morrection as follows: Page 4, line 74, clguim 7, after the Ward snap insert the were! I spring; and that the said Letters Patent should be maxi with this summation themin that the same may conform tn the record of the ease in thaPzttwt @ffice.

Signed atndl smltd this 5th day of September, A. Fl, 1 91% [fiEAL] F. W, H, CLAY, 

